Kai Ko Chen-tung is a Taiwanese actor, singer and film director. Ko won Best New Actor at the 48th Golden Horse Awards and the 12th Chinese Film Media Awards for his starring role in the film You Are the Apple of My Eye, also his film debut. In November 2011, Ko released his debut studio album, Be Yourself. His career was derailed when he was arrested on drug charges in 2014, which led him to be banned in Mainland China.

You Are the Apple of My Eye is a 2011 Taiwanese coming of age romance film. It is based on the semi-autobiographical novel of the same name by Taiwanese author Giddens Ko, who also made his directorial debut with the film. The film stars Ko Chen-tung as Ko Ching-teng, a prankster and a mischievous student who eventually becomes a writer. Michelle Chen stars as Shen Chia-yi, an honor student who is very popular amongst the boys in her class.